WO2011118846A1 - Surface treated steel plate, manufacturing method therefor, and resin-coated steel plate using same - Google Patents

Abstract

Provided is a surface-treated steel plate: having a corrosion-resistant film comprising at least one layer selected from an Ni layer, Sn layer, Fe-Ni alloy layer, Fe-Sn alloy layer and Fe-Ni-Sn alloy layer, on at least one side of the steel plate; and having an adhesive film containing Zr, and further containing 0.01 to 10 parts in total by mass of at least one type of metal element selected from Co, Fe, Ni, V, Cu, Mn and Zn with respect to Zr, on the corrosion-resistant film. This surface-treated steel plate has excellent wet resin adhesion and corrosion resistance, and striation surface defects do not occur. It is therefore possible to constitute a resin-coated steel plate with outstanding characteristics if the surface-treated steel plate is coated with resin. In addition, with this method of producing a surface-treated steel plate, there is no need to use Cr, which is subject to strict environmental regulation.

Description

Surface-treated steel sheet, method for producing the same, and resin-coated steel sheet using the same

The present invention is a surface-treated steel sheet mainly used for containers such as cans after laminating a resin film or the like on the surface or coating a resin-containing paint, particularly in a high-temperature and humid environment. Surface-treated steel sheet having excellent adhesion to the coated resin (hereinafter referred to as wet resin adhesion) and excellent corrosion resistance even when the coated resin is missing, its production method, and resin for this surface-treated steel sheet Relates to a resin-coated steel sheet coated with

Various metal cans such as beverage cans, food cans, pail cans and 18 liter cans use metal plates such as electrolytic chromic acid treated steel plates called tin-plated steel plates or tin-free steel plates. Among these, tin-free steel plates are produced by electrolytic treatment of steel plates in a plating bath containing hexavalent Cr, and are characterized by having excellent wet resin adhesion to resins such as paints.

In recent years, with the increasing awareness of the environment, the use of hexavalent Cr has been restricted worldwide, and there are alternative materials for tin-free steel plates manufactured using a hexavalent Cr plating bath. It has been demanded.

On the other hand, various metal cans have been manufactured by coating metal plates such as tin-free steel plates and then processing them into cans. Instead, a method of processing a resin-coated metal plate coated with a resin such as a plastic film into a can body is frequently used. In this resin-coated metal plate, it is necessary that the resin is strongly adhered to the metal plate. In particular, the resin-coated metal plate used as a beverage can or a food can is subjected to a retort sterilization process after filling the contents. In some cases, the resin does not exfoliate even in a high-humidity environment, and even if the resin is partially lost due to scratching, the contents of the can are damaged and the hole is opened. There is a demand for excellent corrosion resistance that does not cause the occurrence of corrosion.

In response to such a request, the present inventors recently disclosed in Patent Document 1 a Ni layer, a Sn layer, a Fe—Ni alloy layer, a Fe—Sn alloy layer, and a Fe—Ni—Sn alloy layer on at least one surface of a steel plate. After forming a corrosion-resistant film consisting of at least one layer selected from the above, it contains ions containing Ti, and at least one metal selected from Co, Fe, Ni, V, Cu, Mn and Zn Presents that it is possible to produce a surface-treated steel sheet with excellent wet resin adhesion and excellent corrosion resistance without using Cr by forming an adhesive film by cathodic electrolysis in an aqueous solution containing ions containing elements. did.

JP 2009-155665 A

However, streaky surface defects may occur in the surface-treated steel sheet manufactured by the method described in Patent Document 1.

The present invention relates to a surface-treated steel sheet that does not use Cr, has excellent wet resin adhesion and corrosion resistance, and does not generate streak-like surface defects, a method for producing the same, and a resin-coated steel sheet using the surface-treated steel sheet The purpose is to provide.

The inventors of the present invention have intensively studied to achieve the above object. As a result, when forming an adhesive film in Patent Document 1, Zr is contained instead of Ti, and Co, Fe, Ni, V, Cu, Mn and It has been found that it is effective to perform cathodic electrolysis in an aqueous solution containing at least one metal element selected from Zn.

The present invention has been made on the basis of such knowledge, and at least one surface of the steel sheet is selected from a Ni layer, a Sn layer, a Fe—Ni alloy layer, a Fe—Sn alloy layer, and a Fe—Ni—Sn alloy layer. And at least one metal element selected from the group consisting of Co, Fe, Ni, V, Cu, Mn, and Zn. There is provided a surface-treated steel sheet characterized by having an adhesive film containing 0.01 to 10 in total by mass ratio to Zr. In the surface-treated steel sheet of the present invention, it is preferable that the adhesive film further contains P derived from phosphoric acids and / or C derived from a phenol resin in a total mass ratio of 0.01 to 10 with respect to Zr. Further, the Zr adhesion amount of the adhesive film is preferably 3 to 200 mg / m ² per side.

The surface-treated steel sheet of the present invention comprises at least one layer selected from a Ni layer, a Sn layer, a Fe—Ni alloy layer, a Fe—Sn alloy layer, and a Fe—Ni—Sn alloy layer on at least one surface of the steel sheet. After forming the corrosion-resistant film, Zr is contained at 0.008 to 0.07 mol / l (l: liter), and at least one metal selected from Co, Fe, Ni, V, Cu, Mn and Zn It can be produced by forming an adhesive film by cathodic electrolysis at an electric quantity density of 1 to 20 C / dm ² in an aqueous solution containing the elements in a total molar ratio of 0.01 to 10 with respect to Zr.

The surface-treated steel sheet of the present invention has at least one layer selected from a Ni layer, a Sn layer, a Fe—Ni alloy layer, a Fe—Sn alloy layer, and a Fe—Ni—Sn alloy layer on at least one surface of the steel sheet. After forming a corrosion-resistant film comprising Zr in an amount of 0.008 to 0.07 mol / l, and further containing at least one metal element selected from Co, Fe, Ni, V, Cu, Mn and Zn In an aqueous solution containing 0.01 to 10 molar ratios with respect to Zr in total, the current density varies between a current density at which Zr precipitates and a current density at which Zr does not precipitate in a period of 0.01 to 0.4 seconds. A current having a current density at which no Zr is deposited per period is 0.005 to 0.2 seconds, a cycle number is 10 or more, and the total electric density at the current density at which Zr is deposited is 3 to 3 20C / dm ² to become electrolytic It can be prepared by forming the adhesion film by cathodic electrolytic treatment in matter. Here, the upper limit of the current density at which Zr does not precipitate is a value depending on the composition and pH of the aqueous solution used for the cathodic electrolysis. In this manufacturing method, it is possible to use a current whose current density changes to a binary value of a current density at which Zr is deposited and a current density at which Zr is not deposited. At this time, the current density at which Zr does not precipitate is preferably 0 A / dm ² .

In any of the above production methods, the aqueous solution used for the cathodic electrolysis treatment preferably further contains phosphoric acids and / or phenol resins in a total molar ratio of 0.01 to 10 with respect to Zr.

The present invention also provides a resin-coated steel sheet in which the above-described surface-treated steel sheet of the present invention is coated with a resin.

According to the present invention, it is possible to produce a surface-treated steel sheet that does not use Cr, has excellent wet resin adhesion and corrosion resistance, and does not generate streak-like surface defects. The surface-treated steel sheet of the present invention can be used without any problem as an alternative to conventional tin-free steel sheets without being coated with a resin on a container containing oil, organic solvent, paint, or the like. Further, even if the resin is coated to form a resin-coated steel sheet, processed into a can or can lid and exposed to a retort atmosphere, the resin does not peel off. Further, even in a resin missing part such as a scratch, the elution of Fe as a base material is remarkably small, and the corrosion resistance is extremely excellent.

FIG. 1 is a graph showing the relationship between current density and Zr deposition amount in an aqueous solution at pH 4 containing 12.5 g / l potassium hexafluorozirconate and 5 g / l cobalt sulfate heptahydrate.
[FIGS. 2 (a), 2 (b), and 2 (c)] FIG. 2 is a diagram for explaining a 180 ° peel test.

1) Surface-treated steel sheet The surface-treated steel sheet of the present invention is selected from a Ni layer, a Sn layer, a Fe—Ni alloy layer, a Fe—Sn alloy layer, and a Fe—Ni—Sn alloy layer on at least one side of the steel plate. After forming a corrosion-resistant film consisting of at least one layer, the corrosion-resistant film contains Zr and further contains at least one metal element selected from Co, Fe, Ni, V, Cu, Mn and Zn. An adhesive film is formed.

As the material steel plate, a general low carbon cold rolled steel plate for cans can be used. 1.1) Corrosion resistant coating The corrosion resistant coating formed on the steel plate surface is firmly bonded to the base steel plate, Ni layer, Sn layer, Fe—Ni alloy layer, Fe—Sn alloy layer, and Fe—Ni—Sn in order to give excellent corrosion resistance to the steel plate even when the resin is partially lost due to scratching etc. It is necessary to form a film made of a single alloy layer or a multilayer thereof. In the case of the Ni layer, it is preferable that the Ni adhesion amount per one side of the steel plate is 200 mg / m ² or more. In the case of the Fe—Ni alloy layer, it is preferable that the Ni adhesion amount per one side of the steel sheet is 60 mg / m ² or more. In the case of the Sn layer or the Fe—Sn alloy layer, it is preferable that the Sn adhesion amount per one side of the steel sheet is 100 mg / m ² or more. In the case of the Fe—Ni—Sn alloy layer, it is preferable that the Ni adhesion amount per one side of the steel sheet is 50 mg / m ² or more and the Sn adhesion amount is 100 mg / m ² or more.
Here, the measurement of the amount of Ni or Sn attached can be performed by surface analysis using fluorescent X-rays.

Such a corrosion-resistant film can be formed by a known method according to the contained metal element.

1.2) Adhesive film On the corrosion-resistant film, a mass ratio of Zr to at least one metal element selected from Co, Fe, Ni, V, Cu, Mn and Zn in total with respect to Zr By forming an adhesive film containing 0.01 to 10, more preferably 0.01 to 2, excellent wet resin adhesion can be obtained, and the occurrence of streaky surface defects can be reliably prevented. The reason for this is not clear at present, but it is considered that such a metal element is incorporated into a film containing Zr, thereby forming a dense film having a uniform distribution of surface irregularities.

It is preferable that the adhesive film further contains P derived from phosphoric acids and / or C derived from a phenol resin in a total mass ratio of 0.01 to 10 with respect to Zr. This is because when the adhesive film contains P derived from phosphoric acids and / or C derived from a phenolic resin, the coverage of the adhesive film is further improved and the corrosion resistance is improved. The reason why the coatability is improved is not clear at present. This is considered to be due to the covalent bond between the corrosion-resistant film and the adhesive film via oxygen atoms.

The Zr adhesion amount of the adhesive film is preferably 3 to 200 mg / m ² per one side of the steel plate. This, Zr coating weight, the effect of prevention of improvement and streaky surface defects of wet resin adhesion is sufficiently obtained at 3 mg / ^{m 2} or more 200 mg / ^{m 2} or less, when it exceeds 200 mg / ^{m 2} the effect Is saturated and the cost is high. More preferably, it is 20 to 100 mg / m ² .

The total adhesion amount of at least one metal element selected from the group consisting of Co, Fe, Ni, V, Cu, Mn and Zn of the adhesive film should be 10 to 200 mg / m ² per one side of the steel sheet. preferable. If the total adhesion amount of these metal elements is 10 mg / m ² or more and 200 mg / m ² or less, a film with excellent wet resin adhesion and no streak-like surface defects can be formed.

The adhesive film preferably further contains 0. This is because the inclusion of 0 makes the film mainly composed of Zr oxide, which is effective in improving wet resin adhesion and preventing the occurrence of streaky surface defects.

The adhesion amount of Zr, Co, Fe, Ni, V, Cu, Mn, Zn, and P on the adhesive film can be measured by surface analysis using fluorescent X-rays. The amount of C in the adhesive film can be determined by subtracting the amount of C contained in the steel sheet as a background from the value obtained by measuring the total amount of C by gas chromatography. The amount of 0 is not particularly defined, but its presence can be confirmed by surface analysis using XPS (X-ray photoelectron spectroscopy analyzer).

The formation of the adhesive film includes 0.008 to 0.07 mol / l, preferably 0.02 to 0.05 mol / l of Zr, and among Co, Fe, Ni, V, Cu, Mn and Zn In an aqueous solution containing a total of at least one metal element selected from the group consisting of 0.01 to 10, preferably 0.01 to 2.5, and more preferably 0.01 to 2 in terms of molar ratio to Zr. it is possible by cathodic electrolysis at a density 1 ~ 20C / dm ^2. When the concentration of Zr is less than 0.008 mol / l, it is impossible to form a film having excellent wet resin adhesion and no streak-like surface defects. On the other hand, when it exceeds 0.07 mol / l, it becomes difficult to exist in a stable state in an aqueous solution, and there arises a problem that a Zr oxide is generated. When the total concentration of at least one metal element selected from Co, Fe, Ni, V, Cu, Mn and Zn is less than 0.01 in terms of molar ratio, the wet resin adhesion is excellent and streaky surface defects. A film without a film cannot be formed. On the other hand, if it exceeds 10, the effect is saturated and the cost becomes high.

As the aqueous solution containing Zr, an aqueous solution containing fluorozirconic acid ions or an aqueous solution containing fluorozirconic acid ions and a fluorine salt is suitable. Examples of compounds that give fluorozirconate ions include hydrofluoric zirconate, ammonium hexafluoride zirconate, and potassium hexafluorozirconate. As the fluorine salt, sodium fluoride, potassium fluoride, silver fluoride, tin fluoride, or the like can be used. In particular, an aqueous solution containing potassium hexafluorozirconate or an aqueous solution containing potassium hexafluorozirconate and sodium fluoride is preferable because a homogeneous film can be formed efficiently.

Examples of compounds that give Co, Fe, Ni, V, Cu, Mn, and Zn include cobalt sulfate, cobalt chloride, iron sulfate, iron chloride, nickel sulfate, copper sulfate, vanadium oxide sulfate, zinc sulfate, and manganese sulfate. Can be used. At this time, these metal elements are added so that the sum thereof is 0.01 to 10, preferably 0.01 to 2.5, and more preferably 0.01 to 2 in terms of molar ratio to Zr.

In the cathodic electrolysis treatment, the current density may be 5 to 20 A / dm ² and the electrolysis time may be 1 to 5 seconds, but the electric density is preferably 3 to 15 C / dm ² .

Further, when the cathode electrolysis treatment is carried out intermittently by using a current whose current density periodically changes between a current density at which Zr is deposited and a current density at which Zr is not deposited, Better wet resin adhesion is obtained compared to the case of continuous electrolysis. To that end, it is necessary to secure a certain amount of Zr adhesion, but in order to ensure the amount of Zr adhesion required for productivity (line speed) on a commercial base, the period is 0.01 to 0.4 seconds. A current having a current density at which no Zr is deposited per period is 0.005 to 0.2 seconds, a cycle number is 10 or more, and the total electric density at the current density at which Zr is deposited is 3 to 3 Cathodic electrolysis is preferably performed under electrolysis conditions of 20 C / dm ² . By carrying out the electrolytic treatment under these conditions, the current density at which Zr does not precipitate promotes the re-dissolution of the precipitated Zr rather than causing the precipitation of Zr. It is considered that a distributed film is formed and excellent wet resin adhesion is obtained.

The upper limit of the current density at which Zr does not precipitate, that is, the current density at the boundary when Zr does not precipitate and when Zr precipitates, was selected from Zr, Co, Fe, Ni, V, Cu, Mn, and Zn. It depends on the composition and pH of the aqueous solution containing at least one metal element. For example, FIG. 1 shows the relationship between the current density and the Zr deposition amount in an aqueous solution of pH 4 containing 12.5 g / l potassium hexafluorozirconate and 5 g / l cobalt sulfate heptahydrate. In this case, it can be seen that no precipitation of Zr occurs at 0.8 A / dm ² or less. Thus, since the upper limit of the current density at which Zr does not precipitate depends on the composition and pH of the aqueous solution used for the cathodic electrolysis treatment, it is necessary to obtain in advance according to the aqueous solution to be used.

As the current that periodically changes between the current density at which Zr is deposited and the current density at which Zr is not deposited, the alternating current that periodically changes like a sine curve, the current density at which Zr is deposited, and Zr are deposited. It is possible to use a pulse current that changes to a binary value with a current density that does not. In addition, a current obtained by superimposing an alternating current or a pulse current on a direct current can also be used. In addition, when using a pulse current that changes to a binary value of a current density at which Zr precipitates and a current density at which Zr does not precipitate, the current density at which Zr does not precipitate is set to 0 A / dm ² depending on the aqueous solution used. This is more preferable because it is not necessary to previously obtain the upper limit of the current density at which Zr does not precipitate.

In the present invention, it is preferable to perform the above-described cathodic electrolysis in an aqueous solution further containing phosphoric acids and / or phenolic resins in a total molar ratio of 0.01 to 10 with respect to Zr. This is because an adhesive film containing phosphoric acid-derived P and / or phenolic resin-derived C can be formed by cathodic electrolysis in an aqueous solution containing phosphoric acid and / or phenolic resin, as described above. This is because the coverage of the adhesive film is further improved and the corrosion resistance is improved. At this time, as a compound that gives phosphoric acid, orthophosphoric acid or a phosphoric acid compound of a metal element added at the same time may be used, and nickel phosphate, iron phosphate, cobalt phosphate, zirconium phosphate and the like can be used. The phenol resin preferably has a weight average molecular weight of about 3000 to 20000, more preferably about 5000. In addition, the phenol resin may be water-soluble by modifying with amino alcohol.

2) Resin coated steel sheet (laminated steel sheet)
A resin-coated steel sheet can be formed by coating a resin on the surface-treated steel sheet of the present invention. As described above, since the surface-treated steel sheet of the present invention is excellent in wet resin adhesion, this resin-coated steel sheet has excellent corrosion resistance and workability.

The resin coated on the surface-treated steel sheet of the present invention is not particularly limited, and examples thereof include various thermoplastic resins and thermosetting resins. For example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic ester copolymer, olefin resin film such as ionomer, polyester film such as polybutylene terephthalate, or nylon 6 A non-stretched or biaxially stretched thermoplastic resin film such as a polyamide film such as nylon 6,6, nylon 11, or nylon 12, a polyvinyl chloride film, or a polyvinylidene chloride film can be used. When an adhesive is used for lamination, a urethane adhesive, an epoxy adhesive, an acid-modified olefin resin adhesive, a copolyamide adhesive, a copolyester adhesive (thickness: 0.1 to 5. 0 μm) and the like are preferable. Furthermore, a thermosetting coating can be applied to the surface-treated steel sheet side or film side in a thickness range of 0.05 to 2 μm, and this can be used as an adhesive.

Furthermore, modified epoxy paints such as phenol epoxy and amino-epoxy, vinyl chloride-vinyl acetate copolymer, saponified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, epoxy-modified- Epoxyamino-modified, epoxyphenol-modified-vinyl paint or modified vinyl paint, acrylic paint, thermoplastic or thermosetting paint such as synthetic rubber paint such as styrene-butadiene copolymer alone or in combination of two or more. They can be used in combination.

The thickness of the resin coating layer is desirably 3 to 50 μm, particularly 5 to 40 μm. This is because if the thickness is less than the above range, the corrosion resistance becomes insufficient, and if the thickness exceeds the above range, problems are likely to occur in terms of workability.

The formation of the resin coating layer on the surface-treated steel sheet can be performed by any means. For example, it can be performed by an extrusion coating method, a cast film thermal bonding method, a biaxially stretched film thermal bonding method, or the like. In the case of the extrusion coating method, it can be produced by extrusion coating a resin on a surface-treated steel sheet in a molten state and thermally bonding the resin. That is, after melt-kneading the resin with an extruder, the resin is extruded into a thin film from a T-die, and the extruded molten resin film is passed through a pair of laminate rolls together with a surface-treated steel sheet to be pressed and integrated under cooling, and then rapidly cooled. To do. When extrusion coating a multi-layer resin coating layer, use multiple extruders for each layer, merge the resin streams from each extruder in a multi-layer die, and then extrude as in the case of a single layer resin. Just coat it. Moreover, a resin coating layer can be formed on both surfaces of a surface-treated steel sheet by passing a surface-treated steel sheet vertically between a pair of laminate rolls and supplying a molten resin web to both sides thereof.

Such a resin-coated steel sheet can be applied to three-piece cans and seamless cans (two-piece cans) having side seams. The present invention can also be applied to a stay-on-tab type easy open can lid and a full open type easy open can lid.

The above description is merely an example of the embodiment of the present invention, and various modifications can be made within the scope of the claims.

Using the plating baths a and b shown in Table 1 on both sides of a cold-rolled cold-rolled steel plate (thickness 0.2 mm) of cold-rolled steel used for the production of tin-free steel plate (TFS), A corrosion resistant film is formed by the following methods A to D.
A: A cold-rolled steel sheet was annealed at about 700 ° C. in a 10 vol% H ₂ +90 vol% N ₂ atmosphere, subjected to temper rolling with an elongation of 1.5%, then alkaline electrolytic degreasing, and sulfuric acid washing Then, Ni plating treatment is performed using the plating bath a to form a corrosion-resistant film made of a Ni layer.
B: Alkaline electrolytic degreasing of the cold-rolled steel sheet and Ni plating treatment using the plating bath a, followed by annealing at about 700 ° C. in a 10 vol% H ₂ +90 vol% N ₂ atmosphere to diffuse and penetrate the Ni plating Then, temper rolling with an elongation of 1.5% is performed to form a corrosion-resistant film made of an Fe—Ni alloy layer.
C: Alkaline electrolytic degreasing of the cold-rolled steel sheet and Ni plating using the plating bath a, followed by annealing at about 700 ° C. in an atmosphere of 10 vol% H ₂ +90 vol% N ₂ to diffuse and infiltrate the Ni plating Then, after temper rolling with an elongation of 1.5%, degreasing, pickling, Sn plating treatment using the plating bath b, and heat melting treatment for heating and holding above the melting point of Sn are performed. By this treatment, a corrosion-resistant film composed of the Fe—Ni—Sn alloy layer and the upper Sn layer is formed.
D: A cold-rolled steel sheet is subjected to alkaline electrolytic degreasing, annealed and temper-rolled in the same manner as in Condition A, and then subjected to Sn plating using a plating bath b, and then subjected to a heat-melting process for heating and holding above the melting point of Sn. . By this treatment, a corrosion-resistant film composed of the Fe—Sn alloy layer and the upper Sn layer is formed.

In the processing of C and D, a part of Sn plating is alloyed by heat melting treatment. Tables 3 to 5 show the remaining pure Sn remaining without being alloyed.

Next, cathodic electrolysis was performed on the corrosion resistant coatings formed on both surfaces of the steel plate under the conditions of cathodic electrolysis shown in Tables 2 to 5, and dried to form an adhesive coating. 1 to 33 are produced. The surface-treated steel plate No. Nos. 1, 16, 19, 22, and 29 are comparative examples in which the adhesive film does not contain Co, Fe, Ni, V, Cu, Mn, and Zn. No. 30 and 31 are comparative examples without forming a corrosion-resistant film. No. Reference numerals 32 and 33 are comparative examples in which an adhesive film containing Ti and further containing V or Mn is formed on the corrosion-resistant film.

Then, the Zr adhesion amount and Ti adhesion amount of the adhesive film are obtained by fluorescent X-ray analysis in comparison with a calibration plate obtained by chemical analysis of the content in advance. Further, the content of Co, Fe, Ni, V, Cu, Mn and Zn is appropriately measured from the same fluorescent X-ray analysis method as that of Zr and Ti, and from chemical analysis, Auger electron spectroscopic analysis and secondary ion mass spectrometry. Is selected and the mass ratio of Co, Fe, Ni, V, Cu, Mn and Zn to Zr or Ti contained in the adhesive film is evaluated. Also, 0 is No. The presence of all of 1 to 33 can be confirmed by surface analysis by XPS.

These surface-treated steel plates No. An isophthalic acid copolymerized polyethylene terephthalate film having a draw ratio of 3.1 × 3.1, a thickness of 25 μm, a copolymerization ratio of 12 mol%, and a melting point of 224 ° C. was used on both surfaces 1 to 33, and the degree of biaxial orientation of the film (BO Value) is set to 150, that is, the steel sheet feed speed is 40 m / min, the nip length of the rubber roll is 17 mm, and the time from pressure bonding to water cooling is 1 second. 1 to 33 are produced. Here, the nip length is the length in the transport direction of the portion where the rubber roll and the steel plate are in contact. And the produced laminated steel plate No.1. 1 to 33 are evaluated for wet resin adhesion, corrosion resistance, and streak-like surface defects by the following methods.
Wet resin adhesion: Wet resin adhesion is evaluated by a 180 ° peel test in a retort atmosphere at a temperature of 130 ° C. and a relative humidity of 100%. The 180 ° peel test is a test piece (size: 30 mm × 100 mm, both of the front and back surfaces are each n = 1, leaving a film 2 as shown in FIG. As shown in FIG. 2B, a weight 4 (100 g) is attached to one end of the test piece, folded 180 ° to the film 2 side, and left for 30 min. It is a film peeling test. And the peeling length 5 shown in FIG.2 (c) is measured and evaluated, and the average of the peeling length (n = 2) of front and back two surfaces is calculated | required about each laminated steel plate. It can be said that the smaller the peel length 5 is, the better the wet resin adhesion is. However, if the peel length 5 is less than 20 mm, it is evaluated that the excellent wet resin adhesion intended by the present invention is obtained.
Corrosion resistance: Cut the laminate surface of the laminated steel plate to reach the steel plate substrate using a cutter knife, and immerse it in 80 ml of a test solution in which the same amount of 1.5% by mass NaCl aqueous solution and 1.5% by mass citric acid aqueous solution are mixed. Then, it was allowed to stand at 55 ° C. for 9 days, and the corrosion resistance of the cut part (n = 1 on each of the front and back surfaces and n = 2 for each laminated steel sheet) was evaluated as follows. Is good.
◯: No corrosion in n = 2 x: Corrosion in 1 or more of n = 2 Streaky surface defects: The degree of occurrence of streak patterns was visually observed and evaluated as follows.
○: A streak pattern is not confirmed.
X: A streak pattern is confirmed.

The results are shown in Table 6. Laminated steel plate No. which is an example of the present invention. In Nos. 2 to 15, 17, 18, 20, 21, and 23 to 28, all show excellent wet resin adhesion and corrosion resistance, and no streak-like surface defects are observed. In contrast, a laminated steel plate No. 1 as a comparative example. Nos. 1, 16, 19, 22, and 29 have no problem in corrosion resistance, but are inferior in wet resin adhesion. Nos. 30 and 31 have no problem with wet resin adhesion, but have poor corrosion resistance. Laminated steel plate No. 32 and 33 have no problem in wet resin adhesion and corrosion resistance, but a streak pattern is confirmed on the surface.

Using the plating baths a and b shown in Table 1 on both sides of a cold-rolled cold-rolled steel plate (thickness 0.2 mm) of cold-rolled steel used for the production of tin-free steel plate (TFS), A corrosion-resistant film is formed by the methods A to D described above. In the processes C and D, a part of the Sn plating is alloyed by the heat melting process. Tables 7 to 9 show the remaining pure Sn remaining without being alloyed.

Next, cathodic electrolysis was performed on the corrosion-resistant film formed on both surfaces of the steel sheet under the conditions of cathodic electrolysis shown in Tables 7 to 9, and dried to form an adhesive film. 34 to 49 are produced. At this time, the pH of the treatment bath is adjusted with an alkaline solution such as potassium hydroxide or an acidic solution such as sulfuric acid. Further, the surface-treated steel plate No. In 34 to 45, a pulse current is used, and the current density at which Zr does not precipitate is 0 A / dm ² . On the other hand, the surface-treated steel plate No. In Nos. 46 and 47, a pulse current is used, and an example in which the current density at which Zr does not precipitate is not 0 A / dm ² (No. 46) and an example exceeding the upper limit (No. 47) are given based on the result of FIG. ing. Among these surface-treated steel plates, No. Nos. 38, 45 and 47 are outside the range of pulse current conditions in which the electrolysis conditions for cathodic electrolysis are preferred. No. 48 and 49 are comparative examples in which cathodic electrolysis is performed in an aqueous solution containing Ti instead of Zr.

And the adhesion amount of Ni and Sn in the corrosion resistant film and the adhesion amount of Zr and Ti in the adhesive film are obtained by fluorescent X-ray analysis in comparison with a calibration plate obtained by chemical analysis of the adhesion amount in advance. Further, the adhesion amount of Co, Fe, V, and Mn is determined by appropriately selecting a measurement method from the same fluorescent X-ray analysis method as that of Zr and Ti, chemical analysis, Auger electron spectroscopy analysis, and secondary ion mass spectrometry. Also, 0 is No. The presence of all 34 to 49 can be confirmed by surface analysis by XPS.

These surface-treated steel plates No. Laminated steel plates No. 34 to 49 were prepared in the same manner as in Example 1. 34 to 49 are produced. And the produced laminated steel plate No.1. 34 to 49 are evaluated in the same manner as in Example 1 for wet resin adhesion, corrosion resistance, and streaky surface defects.

The results are shown in Table 10. Laminated steel plate No. using a surface-treated steel plate as an example of the present invention. 34 to 47 all show excellent wet resin adhesion and corrosion resistance, and no streak-like surface defects are observed. Further, a current having a period of 0.01 to 0.4 seconds, a current density at which the Zr per period is not deposited is 0.005 to 0.2 seconds, a cycle number of 10 or more, No. ^{2 in} which cathodic electrolysis is carried out under electrolysis conditions in which the total electric quantity density at the current density at which precipitation occurs is 3 to 20 C / dm ² . In 34 to 37, 39 to 44, and 46, the peeling length of wet resin adhesion is 15 mm or less, and particularly excellent wet resin adhesion is obtained. In contrast, a laminated steel plate No. 1 as a comparative example. 48 and 49 both show excellent wet resin adhesion and corrosion resistance, but streak-like surface defects are observed.

Using the plating baths a and b shown in Table 1 on both sides of a cold-rolled cold-rolled steel plate (thickness 0.2 mm) of cold-rolled steel used for the production of tin-free steel plate (TFS), A corrosion-resistant film is formed by the methods A to D described above. In the processes C and D, a part of the Sn plating is alloyed by the heat melting process. Tables 11 and 12 show the remaining pure Sn remaining without alloying.

Next, cathodic electrolysis was performed on the corrosion-resistant films formed on both surfaces of the steel sheet under the conditions of cathodic electrolysis shown in Tables 11 and 12, and dried to form an adhesive film. 50 to 60 are produced. At this time, the pH of the treatment bath is adjusted with an alkaline solution such as potassium hydroxide or an acidic solution such as sulfuric acid. Further, the surface-treated steel plate No. In 54 to 60, a pulse current is used, and the current density at which Zr does not precipitate is 0 A / dm ² . A phenol resin having a weight average molecular weight of 5000 is used as the phenol resin in the treatment bath.

And the Ni and Sn adhesion amount of the corrosion-resistant film and the Zr adhesion amount of the adhesive film are obtained by fluorescent X-ray analysis in comparison with a calibration plate obtained by chemical analysis of the contents in advance. In addition, the content of Co and P is obtained by selecting an appropriate measurement method from the same fluorescent X-ray analysis method as that of Zr, chemical analysis, Auger electron spectroscopy analysis, and secondary ion mass spectrometry, and is contained in the adhesive film. The mass ratio of Co and P to Zr is evaluated. Also, 0 is No. The presence of all of 50 to 60 can be confirmed by surface analysis by XPS. Further, the C amount of the adhesive film is obtained by subtracting the C amount contained in the steel sheet as a background from the value obtained by measuring the total C amount by gas chromatography.

These surface-treated steel plates No. On both sides of 50 to 60, in the same manner as in Example 1, laminated steel plate No. 50 to 60 are produced. And the produced laminated steel plate No.1. For 50 to 60, the wet resin adhesion, corrosion resistance, and streak-like surface defects are evaluated in the same manner as in Example 1.

The results are shown in Table 13. Laminated steel plate No. which is an example of the present invention. From 50 to 60, all showed excellent wet resin adhesion and corrosion resistance, and no streak-like surface defects were observed. In addition, no. In 54 to 60, the wet resin adhesion peel length is 15 mm or less, and particularly excellent wet resin adhesion is obtained. In addition, in the adhesive film containing Zr, spot-like rust may be observed in addition to the cut portion after the corrosion resistance test. However, as in the present invention example, P derived from phosphoric acids or C derived from a phenol resin in the film. When selenium is contained, no point-like rust is recognized.

According to the present invention, a surface-treated steel sheet having excellent wet resin adhesion and corrosion resistance without causing streak-like surface defects can be produced without using Cr, which has strict environmental regulations. The surface-treated steel sheet of the present invention can be used without any problem as a substitute for conventional tin-free steel sheets, and can be used without coating a container containing oil, organic solvent, paint, or the like as a content. Further, even if the resin is coated to form a resin-coated steel sheet, processed into a can or can lid and exposed to a retort atmosphere, the resin does not peel off. Further, even in a resin missing part such as a scratch, the elution of Fe as a base material is remarkably small and the corrosion resistance is extremely excellent. Therefore, it can greatly contribute to the industry.

DESCRIPTION OF SYMBOLS 1 Steel plate 2 Film 3 Part cut out of steel plate 4 Weight 5 Peeling length

Claims (9)

At least one surface of the steel plate has a corrosion-resistant film composed of at least one layer selected from a Ni layer, a Sn layer, a Fe—Ni alloy layer, a Fe—Sn alloy layer, and a Fe—Ni—Sn alloy layer. The film contains Zr, and further contains at least one metal element selected from Co, Fe, Ni, V, Cu, Mn and Zn in a total mass ratio of 0.01 to 10 with respect to Zr. A surface-treated steel sheet characterized by having an adhesive film. The surface-treated steel sheet, wherein the adhesive film further contains P derived from phosphoric acid and / or C derived from a phenol resin in a total mass ratio of 0.01 to 10 with respect to Zr. The surface-treated steel sheet according to claim 1 or 2, wherein the adhesion film has a Zr adhesion amount of 3 to 200 mg / m ² per side of the steel sheet. After forming a corrosion resistant film consisting of at least one layer selected from Ni layer, Sn layer, Fe—Ni alloy layer, Fe—Sn alloy layer and Fe—Ni—Sn alloy layer on at least one surface of the steel plate, Zr 0.008 to 0.07 mol / liter, and at least one metal element selected from Co, Fe, Ni, V, Cu, Mn and Zn in a molar ratio with respect to Zr is 0.01 in total. A method for producing a surface-treated steel sheet, comprising forming an adhesive film by cathodic electrolysis in an aqueous solution containing 10 to 10 at an electric density of 1 to 20 C / dm ² . After forming a corrosion resistant film consisting of at least one layer selected from Ni layer, Sn layer, Fe—Ni alloy layer, Fe—Sn alloy layer and Fe—Ni—Sn alloy layer on at least one surface of the steel plate, Zr 0.008 to 0.07 mol / liter, and at least one metal element selected from Co, Fe, Ni, V, Cu, Mn and Zn in a molar ratio with respect to Zr is 0.01 in total. In an aqueous solution containing 10 to 10, the current density changes between a current density at which Zr precipitates and a current density at which Zr does not precipitate in a period of 0.01 to 0.4 seconds, and a current at which Zr per period does not precipitate Cathodic conditions using an electric current with a density in the range of 0.005 to 0.2 seconds, an electrolytic condition in which the cycle number is 10 or more, and the total electric density at the current density at which Zr is deposited is 3 to 20 C / dm ² Electrolytic treatment and dense Wherein the manufacturing method of the surface treated steel sheet for forming a sex film; wherein the upper limit of the current density Zr does not precipitate is a value that depends on the composition and pH of the aqueous solution used for the cathode electrolytic treatment. 6. The method for producing a surface-treated steel sheet according to claim 5, wherein the current density uses a current that changes into a binary value of a current density at which Zr precipitates and a current density at which Zr does not precipitate. The method for producing a surface-treated steel sheet according to claim 6, wherein a current density at which the Zr does not precipitate is 0 A / dm ² . The surface-treated steel sheet according to any one of claims 4 to 7, wherein the aqueous solution further contains phosphoric acids and / or phenolic resins in a total molar ratio of 0.01 to 10 with respect to Zr. Production method. A resin-coated steel sheet, wherein the surface-treated steel sheet according to any one of claims 1 to 3 is coated with a resin.

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